The present invention relates to an electronic balance, and more particularly to a precision electronic balance made free from ambient temperature variations. Electronic balances are generally devised to weigh a loaded weight by making the weight balanced with a force produced by an electronic force-transducer. The force-transducer consists of a magnetic circuit and an electromagnetic force-coil kept movable in the static-magnetic field made by the magnetic circuit. The electromagnetic force-coil is supplied with a current controlled automatically by an electronic feedback circuit so as to make the force-coil produce current just balancing the weight. The weight value is obtained from measuring the current. An example of such electronic balances is disclosed in the U.S. Pat. No. 4,372,406, while a force-transducer usable in an electronic balance is disclosed, for instance, in the UK patent application GB No. 2 076 543 A.
Electronic balances, particularly precision ones for analytical use have come to show a relative sensitivity of 5.times.10.sup.-7, the ratio of a minimum scaling division to a maximum weighing capacity. On the other hand it is an important disadvantage of electronic balances that the force-transducer and electronic circuit are likely to be affected by the ambient temperature. In the present state of technology, weighed-value fluctuations due to the effect of ambient temperature variations on the force-transducer and electronic circuit can not be suppressed to a value lower than 1.about.2.times.10.sup.-6 /day by a usual method of temperature compensation. In using a precision electronic balance, therefore, the temperature of the whole room must be controlled so as not to fluctuate over 0.5.degree. C. from a constant temperature. The requirement of such severe temperature control has restricted the place where a precision electronic balance can satisfactorily be used.